Bipolar disorder, which is also referred to as manic-depression, is a brain disorder that causes extreme shifts in a person's mood, thought, energy, behavior, and ability to function. The symptoms of bipolar disorder can be are severe, and can result in emotional problems, poor job or school performance, and even suicide. The name “bipolar” comes from the patients' mood swings, which can alternate between the “poles” of mania (highs) and depression (lows). These mood swings can be quite dramatic, from overly “high” and/or irritable to sad and hopeless, and then back again, often with periods of normal mood in between, and severe changes in energy and behavior go along with these changes in mood. Bipolar disorder typically develops in late adolescence or early adulthood. However, some people have their first symptoms during childhood or late in life. This disorder is not always viewed as an illness, and people may suffer for years before proper diagnosis.
Bipolar disorder has been separated into two categories, Type I and Type II, and is typically diagnosed following the guidelines in the Diagnostic and Statistical Manual of Mental Disorders (DSM) Fourth Edition, 1994 (American Psychiatric Association, 1400 K Street NW, Suite 1101, Washington, D.C. 20005-2403 USA). The fourth edition of these guidelines, DSM-IV, identifies the diagnostic features of Bipolar I Disorder as follows.
Bipolar I Disorder (DSM-IV, p. 350)
This disorder is a clinical course that is characterized by the occurrence of one or more Manic Episodes or Mixed Episodes. Often individuals have also had one or more Major Depressive Episodes. Episodes of Substance-Induced Mood Disorder (due to the direct effects of a medication, or other somatic treatments for depression, a drug of abuse, or toxin exposure) or of Mood Disorder Due to a General Medical Condition do not count toward a diagnosis of Bipolar I Disorder. In addition, the episodes are not better accounted for by Schizoaffective Disorder and are not superimposed on Schizophrenia, Schizophreniform Disorder, Delusional Disorder, or Psychotic Disorder Not Otherwise Specified.
The diagnostic features of Bipolar II Disorder are as follows.
Bipolar II Disorder (DSM-IV, p. 359)
This disorder is a clinical course that is characterized by the occurrence of one or more Major Depressive Episodes accompanied by at least one Hypomanic Episode. Hypomanic Episodes should not be confused with the several days of euthymia that may follow remission of a Major Depressive Episode. Episodes of Substance-Induced Mood Disorder (due to the direct effects of a medication, or other somatic treatments for depression, a drug of abuse, or toxin exposure) or of Mood Disorder Due to a General Medical Condition do not count toward a diagnosis of Bipolar I Disorder. In addition, the episodes are not better accounted for by Schizoaffective Disorder and are not superimposed on Schizophrenia, Schizophreniform Disorder, Delusional Disorder, or Psychotic Disorder Not Otherwise Specified.
The following diagnostic criteria, also from the DSM-IV apply.
Criteria for Major Depressive Episode (DSM-IV, p. 327)
A. Five (or more) of the following symptoms have been present during the same 2-week period and represent a change from previous functioning; at least one of the symptoms is either (1) depressed mood or (2) loss of interest or pleasure. Symptoms that are clearly due to a general medical condition, or mood-incongruent delusions or hallucinations should not be included.                Depressed mood most of the day, nearly every day, as indicated by either subjective report (e.g., feels sad or empty) or observation made by others (e.g., appears tearful). Note: In children and adolescents, can be irritable mood.        Markedly diminished interest or pleasure in all, or almost all, activities most of the day, nearly every day (as indicated by either subjective account or observation made by others)        Significant weight loss when not dieting or weight gain (e.g., a change of more than 5% of body weight in a month), or decrease or increase in appetite nearly every day. Note: In children, consider failure to make expected weight gains.        Insomnia or hypersomnia nearly every day.        Psychomotor agitation or retardation nearly every day (observable by others, not merely subjective feelings of restlessness or being slowed down).        Fatigue or loss of energy nearly every day.        Feelings of worthlessness or excessive or inappropriate guilt (which may be delusional) nearly every day (not merely self-reproach or guilt about being sick).        Diminished ability to think or concentrate, or indecisiveness, nearly every day (either by subjective account or as observed by others).        Recurrent thoughts of death (not just fear of dying), recurrent suicidal ideation without a specific plan, or a suicide attempt or a specific plan for committing suicide.        
B. The symptoms do not meet criteria for a Mixed Episode.
C. The symptoms cause clinically significant distress or impairment in social, occupational, or other important areas of functioning.
D. The symptoms are not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication) or a general medical condition (e.g., hypothyroidism).
E. The symptoms are not better accounted for by bereavement, i.e., after the loss of a loved one, the symptoms persist for longer than 2 months or are characterized by marked functional impairment, morbid preoccupation with worthlessness, suicidal ideation, psychotic symptoms, or psychomotor retardation.
Criteria for Manic Episode (DSM-IV, p. 332)
A. A distinct period of abnormally and persistently elevated, expansive, or irritable mood, lasting at least 1 week (or any duration if hospitalization is necessary).
B. During the period of mood disturbance, three (or more) of the following symptoms have persisted (four if the mood is only irritable) and have been present to a significant degree:                Inflated self-esteem or grandiosity.        Decreased need for sleep (e.g., feels rested after only 3 hours of sleep).        More talkative than usual or pressure to keep talking.        Flight of ideas or subjective experience that thoughts are racing.        Distractibility (i.e., attention too easily drawn to unimportant or irrelevant external stimuli).        Increase in goal-directed activity (either socially, at work or school, or sexually) or psychomotor agitation.        Excessive involvement in pleasurable activities that have a high potential for painful consequences (e.g., engaging in unrestrained buying sprees, sexual indiscretions, or foolish business investments).        
C. The symptoms do not meet criteria for a Mixed Episode.
D. The mood disturbance is sufficiently severe to cause marked impairment in occupational functioning or in usual social activities or relationships with others, or to necessitate hospitalization to prevent harm to self or others, or there are psychotic features.
E. The symptoms are not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication, or other treatments) or a general medical condition (e.g., hyperthyroidism).
Manic-like episodes that are clearly caused by somatic antidepressant treatment (e.g., medication, electroconvulsive therapy, light therapy) should not count toward a diagnosis of Bipolar I Disorder.
Criteria for Mixed Episode (DSM-IV, p. 335)
A. The criteria are met both for a Manic Episode and for a Major Depressive Episode (except for duration) nearly every day during at least a 1-week period.
B. The mood disturbance is sufficiently severe to cause marked impairment in occupational functioning or in usual social activities or relationships with others, or to necessitate hospitalization to prevent harm to self or others, or there are psychotic features.
C. The symptoms are not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication, or other treatment) or a general medical condition (e.g., hyperthyroidism).
Criteria for Hypomanic Episode (DSM-IV, p. 338)
A. A distinct period of persistently elevated, expansive, or irritable mood, lasting throughout at least 4 days, that is clearly different from the usual nondepressed mood.
B. During the period of mood disturbance, three (or more) of the following symptoms have persisted (four if the mood is only irritable) and have been present to a significant degree:                Inflated self-esteem or grandiosity.        Decreased need for sleep (e.g., feels rested after only 3 hours of sleep).        More-talkative than usual or pressure to keep talking.        Flight of ideas or subjective experience that thoughts are racing.        Distractibility (i.e., attention too easily drawn to unimportant or irrelevant external stimuli).        Increase in goal-directed activity (either socially, at work or school, or sexually) or psychomotor agitation.        Excessive involvement in pleasurable activities that have a high potential for painful consequences (e.g., engaging in unrestrained buying sprees, sexual indiscretions, or foolish business investments).        
C. The episode is associated with an unequivocal change in functioning that is uncharacteristic of the person when not symptomatic.
D. The disturbance in mood and the change in functioning are observable by others.
E. The episode is not severe enough to cause marked impairment in social or occupational functioning, or to necessitate hospitalization, and there are no psychotic features.
F. The symptoms are not due to the direct physiological effects of a substance (e.g., a drug of abuse, a medication, or other treatment) or a general medical condition (e.g., hyperthyroidism).
Hypomanic-like episodes that are clearly caused by somatic antidepressant treatment (e.g., medication, electroconvulsive therapy, light therapy) should not count toward a diagnosis of Bipolar II Disorder.
Current drug therapy for bipolar disorder includes the use of lithium or valproic acid; however side effects are frequent and troublesome, and patients do not respond fully, leading to frequent recurrences of mania and depression.